• Title/Summary/Keyword: U-Factor

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Evaluation of Fracture Toughness of Al alloys for Propulsive Engine using Strain Measurement (변형률 측정을 이용한 추진기관용 Al 합금의 파괴인성 평가)

  • 김재훈;김덕회;임동규;박성욱;문순일
    • Journal of the Korean Society of Safety
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    • v.17 no.3
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    • pp.13-21
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    • 2002
  • The tincture toughness is evaluated by using U(compact tension) and 3PB(three point bending) specimens of AI alloys far propulsive engine. To evaluate the static fracture toughness, strain gage method is used. The static fracture toughness obtained from the strain measurement is compared with the results by ASTM standard and FEM analysis. For the reliable evaluation of fracture toughness, strain gages are attached at various positions.

Action of lysophosphatidylcholine in U937 human monocytes

  • Yun, Mi-Ran;Im, Dong-Soon
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.269.2-270
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    • 2002
  • Atherosclerosis is a main cause of cardiovascular diseases (that is angina. hypertension. cardiac infarction) and stroke. High level of low-density lipoproteins (LDL) in blood has been implicated as an important factor of atherosclerosis progression. Recently researches in endothelial cells unveiled the roles of Iysophosphatidylcholine (LPC). a constituent of oxidized LDL in atherosclerosis. (omitted)

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Double Circuit Simultaneous Fault Analysis (이중선로의 동시사고를 고려한 상정사고해석)

  • Kim, J.U.;Moon, Y.H.;Lee, J.G.
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.136-138
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    • 2002
  • In this paper, we propose the analysis method of the Double Circuit Simultaneous Fault. To improve the accuracy and the promptness of the coontingency analysis, we reformed the Peterson method and extended the Sherman-Morrison equation. We also used the table of trigono -metric factor of Jacobian matrix before the fault, to compute the inverse matrix needed in the loadflow calculation.

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A Study on The U Control of Resonant Inverters (공진형 인버터의 PWM 제어에 관한 연구)

  • 유완식;조규민
    • Proceedings of the IEEK Conference
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    • 2000.06e
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    • pp.17-20
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    • 2000
  • Usually, in many applications, high frequency resonant inverters are used, and the PAM(Pulse Amplitude Modulation), PFM(Pulse Frequency Modulation) or PWM(Pulse Width Modulation) techniques are used to control the output power of resonant inverters. In this paper, a new switching scheme is proposed as a PWM control method. With the proposed method, it can be obtained that unity output displacement factor under the variable resonant frequency. The detail algorithm of the proposed PWM switching scheme and its charicteristics are discussed. And the validity of the proposed method is confirmed with the experimental results.

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DIGITAL CONTROL OF SINGLE PHASE BUCK-BOOST CONVERTER BY PULSE AREA MODULATION

  • Kim, T.J.;Byun, Y.B.;Joe, K.Y.;Kim, C.U.
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.654-657
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    • 1998
  • This paper is described a digital implementation of a pulse area modulation (PAM) method for a unity-power-factor buck-boost converter. A digital controller is designed and implemented by a Digital Signal Processor(DSP) to replace the analog control circuit for PAM. Experimental results are presented and compared with simulations.

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A study on the functional transition of Korean rolling stock's window pane. (한국 철도차량 창호유리의 기능적 변천에 대한 고찰)

  • Lee, Heung-Jae;Chang, Dae-Sung
    • Proceedings of the KSR Conference
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    • 2009.05b
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    • pp.323-337
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    • 2009
  • This paper researched the adiabatic characteristic, safety and sound insulation characteristic of rolling stock window pane type and transition process of korean train vehicle window glass, and also including investigating a hereafter course of development. The window pane have provided the romantic feeling and the external scenery of train travel to the passenger in period of korea 110 year railway history. From the adiabatic viewpoint, this paper reviewed heat conductivity(U-value) and solar factor according to window pane type, including the safety and sound transmission loss of window pane.

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